Agricultural header with ground engaging gauge member for above ground cutting

ABSTRACT

A harvesting header is operable in a first mode of operation by engagement of a skid at the cutter bar for cutting along the ground. A gauging system operable in a second mode includes four ground engaging members supporting the header such that the cutter bar skid plate is at a controlled distance from the ground. The ground engaging members include a long skid and removable gauge wheels are carried on an elongate beam pivoted adjacent the cutter bar and extending to the rear of the frame and adjustable by an upstanding telescopic mast up to a position to allow the cutter bar to run on the ground. A resilient suspension can be provided at the rear of the beam at the junction to the post. The location under the table allows a very high adjustment of the cutter bar in the second mode.

FIELD OF THE INVENTION

The present invention relates to an agricultural header for cutting astanding crop where the header includes ground engaging gauge members inthe form of skids or wheels for supporting the cutter bar at a positionspaced from the ground.

BACKGROUND

U.S. Pat. No. 6,675,568 by Patterson et al discloses and U.S. Pat. No.8,245,489 by Talbot discloses a height control arrangement using gaugewheels supported at opposing ends of a rigid header. The gauge wheelsserve to minimize any substantial deviations from a central controlledheight of the header at the outboard ends of the header, however thesystem is only effective when used on a rigid header or a flexibleheader which is kept rigid. Published Application 2018/0183461 publishedJun. 30, 2016 by Neudorf discloses a gauge wheel system for attachmentto a harvesting header. The disclosures of the above documents are allincorporated herein by reference.

SUMMARY OF THE INVENTION

According to one aspect of the invention there is provided a cropharvesting header comprising:

a main frame structure extending across a width of the header formovement in a forward direction generally at right angles to the widthacross ground including a crop to be harvested;

a mounting assembly for carrying the main frame structure on apropulsion vehicle;

a crop receiving table carried on the main frame structure across thewidth of the header;

a cutter bar across a front of the table arranged to move through thecrop in a cutting action and carrying a sickle knife operable forcutting the crop as the header is moved forwardly for depositing thecrop onto the table;

a crop transport system on the table for moving the cut crop toward adischarge location of the header;

a skid element on the main frame structure for engaging the ground so asto receive lifting forces from the ground;

the skid element located behind the cutter bar and extending along thelength of the cutter bar so that the cutter bar is supported adjacentthe ground for cutting crop close to the ground as the skid elementslides over the ground;

the harvesting header being operable in a first mode of operation withthe skid element engaging the ground and the cutter bar adjacent theground and in a second mode of operation with the skid element and thecutter bar raised away from the ground;

and at least one ground engaging gauge member having a surfacearrangement engaging the ground at a position rearwardly of the cutterbar and in the second mode of operation maintaining the cutter barsupported away from the ground;

the ground engaging member being carried on a mounting assemblycomprising an elongate support member connected at a forward endadjacent to and rearwardly of the cutter bar for pivotal movement aboutan axis parallel to the cutter bar and extending rearwardly therefrom;

the elongate support member being arranged to be raised and lowered toraise and lower the surface arrangement;

wherein the surface arrangement comprises a skid surface which extendseffectively as a continuous slide surface which slides over the groundfrom a front edge at a position adjacent the cutter bar to a position atleast adjacent to the rear edge of the table.

Preferably the skid surface is arched both longitudinally andtransversely.

According to a further aspect of the invention there is provided a cropharvesting header comprising:

a main frame structure extending across a width of the header formovement in a forward direction generally at right angles to the widthacross ground including a crop to be harvested;

a mounting assembly for carrying the main frame structure on apropulsion vehicle;

a crop receiving table carried on the main frame structure across thewidth of the header:

a cutter bar across a front of the table arranged to move through thecrop in a cutting action and carrying a sickle knife operable forcutting the crop as the header is moved forwardly for depositing thecrop onto the table;

a crop transport system on the table for moving the cut crop toward adischarge location of the header;

a skid element on the main frame structure for engaging the ground so asto receive lifting forces from the ground;

the skid element located behind the cutter bar and extending along thelength of the cutter bar so that the cutter bar is supported adjacentthe ground for cutting crop close to the ground as the skid elementslides over the ground;

the harvesting header being operable in a first mode of operation withthe skid element engaging the ground and the cutter bar adjacent theground and in a second mode of operation with the skid element and thecutter bar raised away from the ground;

and at least one ground engaging gauge member having an engagementsurface arrangement to engage the ground at a position rearwardly of thecutter bar and in the second mode of operation maintaining the cutterbar supported away from the ground;

the ground engaging member being carried on a mounting assemblycomprising an elongate support member connected at a forward endadjacent to and rearwardly of the cutter bar for pivotal movement aboutan axis parallel to the cutter bar and extending rearwardly therefrom:

the elongate support member being arranged to be raised and lowered toraise and lower the surface;

wherein the engagement surface arrangement comprises:

-   -   a skid surface carried on the elongate support member which        extends effectively as a continuous slide surface which slides        over the ground extending from a front edge at a position        adjacent the cutter bar to a rear surface;    -   and at least one ground engaging wheel arrangement carried on        the elongate support member.

Preferably the wheel arrangement is removable to allow the skid surfaceto slide on the ground. That is the system can be used with a skid inmuddy or heavy conditions or with a wheel for better movement over theground when the wheels do not become too mired.

Preferably in another important aspect which can be used independentlyof other features described herein, there is provided a resilientsuspension arrangement which provides movement between the groundengaging member, either whether this is a wheel or a skid, and themounting to the frame of the header. In one embodiment this is providedat the rear of the elongate support member so as to allow the supportmember to pivot upwardly and downwardly in a resilient suspensionmovement relative to its pivot at the forward end. Preferably this isprovided as a pivotal link at the connection of the member to theadjustment post at the rear of the frame. Alternatively in anotherembodiment the suspension can be provided between the elongate supportmember and the wheel arrangement allowing up and down floating movementof the wheel relative to the elongate member. This may counteracttendency for the wheels to dance over the surface causing undesirablemotion of the cutter bar.

Preferably the ground engaging wheel arrangement comprises a pair ofwheels each on a respective side of the skid with transverse axis ofrotation across the top of the skid allowing the wheels to rise relativeto the skid.

According to a further aspect of the invention there is provided a cropharvesting header comprising:

a main frame structure extending across a width of the header formovement in a forward direction generally at right angles to the widthacross ground including a crop to be harvested;

a mounting assembly for carrying the main frame structure on apropulsion vehicle;

a crop receiving table carried on the main frame structure across thewidth of the header;

a cutter bar across a front of the table arranged to move through thecrop in a cutting action and carrying a sickle knife operable forcutting the crop as the header is moved forwardly for depositing thecrop onto the table;

a crop transport system on the table for moving the cut crop toward adischarge location of the header;

a skid element on the main frame structure for engaging the ground so asto receive lifting forces from the ground;

the skid element located behind the cutter bar and extending along thelength of the cutter bar so that the cutter bar is supported adjacentthe ground for cutting crop close to the ground as the skid elementslides over the ground;

the harvesting header being operable in a first mode of operation withthe skid element engaging the ground and the cutter bar adjacent theground and in a second mode of operation with the skid element and thecutter bar raised away from the ground;

and at least one ground engaging gauge member having an engagementsurface arrangement engaging the ground at a position rearwardly of thecutter bar and in the second mode of operation maintaining the cutterbar supported away from the ground;

the ground engaging member being carried on a mounting assemblycomprising an elongate support member connected at a forward endadjacent to and rearwardly of the cutter bar for pivotal movement aboutan axis parallel to the cutter bar and extending rearwardly therefrom;

the elongate support member being arranged to be raised and lowered toraise and lower the surface;

wherein the engagement surface arrangement comprises at least one groundwheel mounted on the elongate support member for rotation about an axisparallel to the cutter bar;

and wherein there is provided a resident suspension arrangement whichprovides movement between the ground engaging member and the mounting tothe frame of the header.

In one embodiment this is provided at the rear of the elongate supportmember so as to allow the support member to pivot upwardly anddownwardly in a resilient suspension movement relative to its pivot atthe forward end. Preferably this is provided as a pivotal link at theconnection of the member to the adjustment post at the rear of theframe. Alternatively in another embodiment the suspension can beprovided between the elongate support member and the wheel arrangementallowing up and down floating movement of the wheel relative to theelongate member. This may counteract tendency for the wheels to danceover the surface causing undesirable motion of the cutter bar.

The arrangements defined above are preferably used in a headerconstruction wherein;

the main frame structure includes a center frame portion, a first wingframe portion and a second wing frame portion;

the first wing frame portion is connected to the center frame portion bya first pivot coupling which provides pivotal movement of the first wingframe portion relative to the center frame portion about a first pivotaxis extending in a plane parallel to the forward direction;

the first pivot coupling acts to support weight from the first wingframe portion while outboard weight from the first wing frame portionoutboard of the first pivot coupling rotates the first wing frameportion about the first pivot coupling in a downward direction;

the second wing frame portion is connected to the center frame portionby a second pivot coupling which provides pivotal movement of the secondwing frame portion relative to the center frame portion about a secondpivot axis extending in a plane parallel to the forward direction;

the second pivot coupling acts to support weight from the second wingframe portion while outboard weight from the second wing frame portionoutboard of the second pivot coupling rotates the second wing frameportion about the second pivot coupling in a downward direction;

the mounting assembly includes a float suspension system connected tothe center frame portion providing a variable lifting force from thepropulsion vehicle acting to support the main frame structure forfloating movement relative to the propulsion vehicle;

a first interconnecting float linkage is connected between the centerframe portion and the first wing frame portion which communicates afirst variable lifting force from the center frame portion to the firstwing frame portion against the outboard weight of the first wing frameportion;

a second interconnecting linkage is connected between the center frameportion and the second wing frame portion which communicates a secondvariable lifting force from the center frame portion to the second wingframe portion against the outboard weight of the second wing frameportion;

in the first mode of operation with the skid element engaging theground, the float suspension system and first and second interconnectinglinkages provide a downforce from the skid element on the ground whichis balanced between the center frame portion and the first and secondwing frame portions.

However the header can also be of a structure which uses a rigid frameor where the frame is fixed so as to be rigid when used in a particularmode.

It is more preferable that the cutting height in the second mode isgreater than 14 inches.

Preferably in this arrangement the first and second ground engagingmembers are mounted at respective outer ends of the first and secondwing frame portions additional ground engaging members are mounted onthe first wing frame portion closely adjacent to the pivot axis andclosely adjacent the pivot axis, and the center frame portion issupported only by said float suspension system and not by any additionalground engaging members.

Preferably each of the elongate support members extends rearwardly underthe table to a rear end rearward of the table and there is provided anupstanding extendible member connected at a lower end to the elongatesupport member and to the frame structure above the lower end andrearward of the table to raise and lower the cutter bar relative to theground.

Preferably the extendible member comprises a pair of telescopic memberswith an outer with an inner member slidable within an outer member,wherein the inner member has a plurality of longitudinally spaced holesfor receiving a pin of the outer member to locate the inner and outermembers at an extension position defined by the selected hole, whereinthe holes are spaced transversely of the inner member and the pin iscarried on a rotatable member which acts when rotated to move the pintransversely across the outer member so that the transverse position ofthe pin when rotated acts automatically to select one of the holes ofthe inner member.

Preferably the main frame structure includes a frame beam and aplurality of frame members located at spaced positions across the mainframe structure;

each frame member extending from the frame beam in a first portiondownwardly behind the table and in a second portion forwardly under thetable to support the cutter bar;

the second portion forming a channel member with a downwardly facingopen face:

the elongate support members each being located in a second portion of arespective one of said frame members and extending rearwardly under thetable.

Preferably each of the ground engaging surface arrangements is locatedunder the table.

Thus one key feature is that the system mounts a skid or skid and wheelon a long arm which is attached to an upstanding actuator at the rear ofthe frame. Another key feature relates to the location and arrangementof the skid and wheel in relation to the fact that it is pivoted at thefront on a lug at the frame and is carried on a beam which is attachedto an upstanding adjustable leg (cylinder or telescope) at the back ofthe frame.

Another key feature relates to the location and arrangement of the skidand/or wheel so that the wheel can be fully retracted to allow theheader to operate in the first mode with the cutter bar and skid elementon the ground.

Another key feature relates to the long skid which extends from thepivot just behind the cutter bar right back to the rear of the table orat the upstanding adjustment post.

One system uses four wheel assemblies (one at each end of the header andone adjacent to or more particularly just outside or just inside of thetwo hinge locations near the center of the header. The wheel assembliespivot near the cutter bar and have a short skid that is part of thestructure that the header rides on when cutting directly on or close tothe ground. The adjustment of all four wheel assemblies is done at therear of the header.

The long skid, like the wheel assembly, is located at each end of theheader and also near each hinge point for a total of four skids. Theseskids also pivot at the cutter bar with an adjustment mechanism at therear of the header.

For the height adjustment of the wheel/skids, this can be effected by amechanical adjustment using a telescoping tube with a series of holesand a pin that can be used to position the wheels or skids to apredetermined height. A second option is the use of hydraulic cylindersthat replace the mechanical adjuster and a switch in the combine cabthat allows the operator to adjust the wheel height using the combine'shydraulics.

For both the wheels and the skids using either the mechanical orhydraulic adjuster, a maximum out height of approximately 14 to 18inches can be achieved. In addition, with the wheels or skids beingfully retracted while remaining in place on the header, the operator cancut with the cutter bar/skid element touching the ground without everneeding to remove the wheels/skids from the header.

The three section frame is designed to cut on the ground and such thatthe cutter bar pressure is consistent or balanced across the full lengthof the cutter bar by means of a balance linkage that uses the weight ofthe header to balance the weight of the wings. This works very well forcrops like soybeans, peas, lentils, where it is desirable to cut asclose to the ground as possible. In these crops, the cutter bar isskidded along the ground and the flex balance linkage and header floatsystem allow the header to follow contours with minimal pressure betweenthe cutter bar and the ground. Current standard skid shoes provide somecutter bar height adjustment in the order of up to 5 inches.

In crops like cereals it is sometimes desirable to cut at a height of upto 14 to 18 inches while following the ground contour. Furthermore, itis desirable to easily go from cutting at this height, and back tocutting on the ground with minimal effort. It is thus desirable for thedevice that allows for cutting off the ground to stay on the header whencutting on the ground, and for the adjustment to be quick and easy.

The device includes contour wheels or long skid shoes. It consists offour separate assemblies located such that the skid shoe or wheelassembly make contact with the ground and cause the header to flex andfollow the contour of the ground, much like the header does when cuttingon the ground. The locations of the wheels or long skid shoes is suchthat they provide enough of a moment about the virtual balance points ofthe flex header to overcome friction and cause the header to flex. Thisvirtual balance point is located on the header wing, approximately onethird the distance from the hinge point to the end of the header.

There are a total of four wheel assemblies across the width of theheader. Two are at each end of the header, and two are near the hingepoints. These locations ensures enough moment about the virtual balancepoint of the header to overcome friction and cause the header to flex.This allows the operator to use the header while in flex mode in orderto achieve better ground following while cutting as high as 18 inchesoff the ground. Ground following was previously only possible whilecutting with the cutter bar resting on the ground or else on the shortskid shoes for a maximum height of 5 inches.

The wheel assemblies can also be used on a header that does not have aflexing frame in that the frame is rigid or the flexing action is lockedout. In this case, there may be only two assemblies used and the wheelsallow the operator to maintain consistent cut height from pass to pass,however cut height variation can still occur due to changing groundcontours across the width of the header.

The wheel assembly contains an isolator or suspension system to aid ineliminating header bounce and stress on components as the wheels travelover bumps and other incompressible objects. One embodiment of theisolator consists of a torsional rubber isolator which is mounted to theelongate support member that spans from the cutter bar to the rearadjuster. In this case, the wheel assembly contains two links bolted tothe torsional isolator. As the wheel strikes an object, the linksconvert the force into a moment which causes the isolator to rotate andabsorb the load. Other means of providing shock absorption such as arubber block, or spring and shock absorber or accumulator can be used.

The means of adjusting the height of the wheel assembly can be a manualadjuster or a hydraulic wheel height adjustment system. With the manualadjuster, the operator sets all four adjusters to a height which isclose to the desired cut height and fine adjustments can then be made tothe cut height by changing the tilt of the header using the tiltcylinder that attaches the header to the adapter. With the hydraulicadjustment which contains four hydraulic cylinders in a series circuitin a master slave arrangement, and a switch in the combine cab, theoperator can adjust the height of the wheels by actuating the cylindersusing the in cab switch while harvesting and can adjust the tilt toobtain an increase in the height using the same switch.

One embodiment of the manual adjuster includes two telescoping tubeswith a pin adjustment system to lock the position. In one embodiment,the outer tube utilizes a series of holes in a circular pattern witheach of the holes aligning with one of the holes on the inner tube. Thisarrangement allows the user to select the height of the adjuster bypulling the pin and rotating the pin holder to the desired setting afterwhich the inner tube can either be extended or retracted until the pinengages in the hole on the inner tube.

Where the ground engaging member comprises a long skid shoe, thiscomprises a skid member positioned such that the header rides on theshoes when in cutting position. The operator may choose to retract theshoes such that the header can cut on the ground, effectively removingthe long skid shoes from operation. This enables the operator to adjustcut height such that a desired stubble length can be achieved. Theembodiment shown allows for a stubble height ranging from 1.25 inch upto 14 inches. This allows a flexible or rigid header to maintain aconsistent cutter bar to ground spacing. In the case of a rigid header,cut height can still vary due to uneven ground across the full width ofthe header. The skid may use metal, poly, or other desirable material asthe ground contacting surface. This surface may be either permanent orreplaceable. The means of adjusting the cut height is the same asdescribed above with the contour wheels by means of a manual orautomatic method, either using hydraulic or electric components. Thelong shoe may either be integrated into standard short skid shoes nearthe front of the header, or exist in addition to short standard skidshoes.

In another embodiment the device can comprise the long skid shoe, withthe addition of a ground-contacting wheel or wheels mounted on each sideof the skid.

The wheels can be permanently attached to the skid shoe, removable, orretractable as desired. The wheels may be supported in a variety ofways, including but not limited to a rotational damping arm. The wheelmay consist of a variety of materials, including a solid material or apneumatic wheel. The wheel may be fixed position or include anadjustable member such that the wheel's position in proximity to theshoe may be altered. The wheel may be used to increase the stubbleheight beyond the range of the shoe. In this embodiment, 18 inches canbe achieved using the wheels. The wheel offers all of the benefits ofthe skid shoe, while increasing the life of the device in abrasiveconditions, as well as reducing friction and increasing cut height.

Various embodiments of the invention will now be described inconjunction with the accompanying drawings in which:

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a rear elevational view of a prior art multi-section header.

FIG. 2 is a top plan view of the prior art multi-section headeraccording to FIG. 1.

FIG. 3 is an end elevational view of the multi-section header accordingto FIG. 1.

FIG. 4 is a schematic representation of the balancing linkage of themulti-section header according to FIG. 1.

FIG. 5 is a schematic elevational view of the balancing linkage inrelation to the suspension system supporting the header according toFIG. 1 on the feeder house of a combine harvester.

FIG. 6 is a isometric view of one gauge wheel assembly for use in theharvesting header of FIGS. 1 to 5 according to the invention.

FIG. 7 is a side elevational view of the gauge wheel assembly of FIG. 6located on a cross-sectional view of the header of FIGS. 1 to 5 showingthe gauge wheel in the retracted position with the cutter bar in theground position of the first mode.

FIG. 8 is a side elevational view of the gauge wheel assembly of FIG. 6located on a cross-sectional view of the header of FIGS. 1 to 5 showingthe gauge wheel in the extended position with the cutter bar in themaximum raised position of the second mode.

FIG. 9 is an enlarged view of the wheels and suspension of theembodiment of FIGS. 6 to 8.

FIG. 10 is an enlarged view of the extendible post of the embodiment ofFIGS. 6 to 8.

FIG. 11 is a further enlarged view of the extendible post of theembodiment of FIGS. 6 to 8.

FIG. 12 is a isometric view of a second embodiment of one gauge wheelassembly for use in the harvesting header of FIGS. 1 to 5 according tothe invention where the resilient suspension arrangement is located atthe rear.

FIG. 13 is a cross-sectional view along the lines 13-13 of theembodiment of FIG. 12.

FIG. 14 is a cross-sectional view along the lines 14-14 of theembodiment of FIG. 12.

In the drawings like characters of reference indicate correspondingparts in the different figures.

DETAILED DESCRIPTION

Referring to the accompanying figures, there is illustrated a gaugesystem generally indicated by reference numeral 5. The gauge system isparticularly suited for use with an agricultural header 10 manufacturedby Macdon Industries Ltd. under the model number FD70/FD75/FD1/FD2. U.S.Pat. No. 6,675,568 by Patterson et al, the disclosure of which isincorporated herein by reference discloses the general operation of theheader. For convenience, FIGS. 1 through 3 from U.S. Pat. No. 6,675,568are attached herewith and some of the description with regard tooperation of the header from U.S. Pat. No. 6,675,568 is reproduced inthe following.

FIGS. 1 and 2 show in rear elevational view and in plan viewrespectively the header 10 carried on an adapter 11 attached to thefeeder house 12 of a combine harvester. In FIG. 1 the adapter is omittedfor convenience of illustration.

The header 10 includes a frame 13 defined by a main rear beam 14 and aplurality of forwardly extending arms 15 which extend downwardly fromthe beam 14 and then forwardly underneath a table 16 which extendsacross the header. At the forward end of the table 16 is provided acutter bar 17. On top of the table 16 is provided a draper transportsystem 18 which carries the crop from the cutter bar across the headerto a discharge location at the feeder house 12. The draper thus includetwo side drapers extending from respective ends of the header inwardlytoward the feeder house and a center adapter section 18B which acts tofeed the crop from the side drapers 18A rearwardly to the feederhousing.

Reference is made to prior application Ser. No. 09/810,425 filed Mar.19, 2001 and to application Ser. No. 09/965,119 filed Sep. 28, 2001which disclose details of the adapter and its inter relation to the sidedrapers 18A, the disclosure of which is incorporated herein byreference.

The header further includes a reel 19 including a beam 19A on which ismounted a plurality of reel bats (not shown) which are carried on thebeam 19A for rotation with the beam around the axis of the beam. Thebeam is carried on reel support arms 19B which extend from the beamrearwardly and upwardly to a support bracket attached to the transversemain beam 14. The reel arms can be raised and lowered by hydrauliccylinders 19D connected between the respective arm and the beam 14.

In the embodiment shown the reel is mounted on three arms 19B includingtwo arms at the ends of the header and a single center arm. Howeveradditional arms may be provided so that there are four such arms withtwo center arms being spaced apart either side of the adapter 11. It iswell known to provide an arrangement of the beam 19A and the bats whichaccommodate flexing movement of the reel so that one end can be higherthan the other end without damaging the bats or the reel structure.Various different arrangements for accommodating such flexing movementare known and can be incorporated into the arrangement described herein,as is well known to one skilled in the art.

The adapter 11 provides a center support for the header at a centerframe portion 10A and comprises a frame 20 which attaches to the feederhouse 12 and carries at its lower end a pair of forwardly extendingpivotal arms 21 which extend forwardly underneath respective ones of theframe members 15 of the header. The pivotal arms 21 can pivot upwardlyand downwardly about a respective pivot pins 23 each independently ofthe other arm. Each arm is supported by a respective spring 24 carriedon a respective stub arm 25 attached to the respective arm 21. Thus thespring 24 provides tension on the stub arm 25 pulling it upwardly aroundthe pin 23 which acts to pull up the respective arm 21 and provide alifting force underneath the header at a lifting point partway along therespective frame member 15 and underneath the draper 18 and the table16.

At the center of the adapter is provided a link 26 which extends fromthe frame 20 forwardly to the central bracket 19C of the beam armsupport brackets. The link 26 is provided in the form of a hydraulictilt cylinder which allows adjustment of the length of the cylinder thuspivoting the header forwardly and rearwardly about the support point ofthe arms 21 on the underside of the header. Thus the attitude of theheader, that is the angle of the table 16 to the horizontal can betilted by operation of the cylinder forming the link 26.

In addition the attitude of the header about an axis extending forwardlyof the direction of movement that is at right angles to the transversebeam 14 is effected by the independent pivotal movement of the arms 21provided by the springs 24 which act as a floatation system. In additionthe whole header can float upwardly and downwardly on the springs 24with the link 26 pivoting to accommodate the upward and downwardmovement and the arms 21 pivoting about the respective pin 23.

The table 16 provides behind the cutter bar 17 a skid plate 16Atypically including a polymeric wear shield which is arranged to engagethe ground. Thus upward force is provided from the ground which tends tolift the header taking weight off the support springs 24. In practicethe springs are adjusted so that the springs act to support the majorityof the weight of the header leaving a relatively small proportion of theweight to rest on the ground. Thus the header can float upwardly anddownwardly as the ground provides areas of different height with one endof the header being movable upwardly independently of the other end byindependent flexing of the springs 24. Thus the header tends to followthe ground level.

The header is formed in a number of sections which are independentlypivotal each relative to the next and in which adjustment of the liftingforce provided by the springs 24 is transferred to each of the sectionsproportionally so that each section can float upwardly and downwardlyand each section applies a force to the ground which is proportional tothe total force of the whole header.

Thus the beam 14 is divided into a number of separate pieces dependingupon the number of sections of the header. In the embodiment shown thereare three sections including a center frame portion or section 10Acarried on the propulsion vehicle by the adapter or center support 11, afirst wing frame portion or section 10B and a second wing frame portionor section 10C. The center section 10A is mounted at the adapter so thatthe arms 21 extend into engagement with the center section. The wingsections are pivotally connected to the center section such that eachcan pivot upwardly and downwardly about a respective pivot axisgenerally parallel to the direction of movement.

Thus the beam 14 is split into three portions each co-operating with arespective one of the sections 10A, 10B and 10C and defining a main beamtherefor. Each section of the beam 14 includes respective ones of theframe members 15 which support the respective portion of the table. Thusas best shown in FIG. 1, there is a break between the beam sections 14of the center section 10A and one wing section 10B. The end most framemember 15A of the wing section 10B is arranged at the break. The endframe member 15B of the center section 10A is spaced inwardly from thebreak leaving space for a pivot coupling 27 extending from the framemember 15A to the frame member 15B and defining a pivot pin 27A lying onthe pivot axis between the wing section 10B and the center section 10A.In a rear elevational view, the cutter bar 17 is also visible underneaththe header at the forward end of the frame members 15 and at the frontof the table 16.

In the embodiment shown the cutter bar 17 is split at a junction lyingalong the axis of a hinge pin so as to provide a pivot within the cutterbar allowing the cutter bar to bend at the junction.

In an alternative arrangement (not shown) the cutter bar can be formedin a manner which allows it to flex on the axis of the pin thus avoidingthe necessity for a break in the cutter bar.

The cutter bar is of conventional shape including a U shaped member withgenerally horizontal legs and a front curved nose to which is attachedthe knife support flange of a conventional nature. The knife supportflange includes a plurality of holes for mounting conventional knifeguards.

A bridging link is connected across the break so as to hold the sectionsof the cutter bar 17 aligned while the pivotal movement occurs. The linkcomprises a plate welded to one part of the cutter bar with the link orplates spanning the break and extending to a pin which is welded to theother part of the cutter bar with the link being held in place by a nut.

Thus the two sections 10A and 10B are supported each relative to theother for pivotal movement of the wing section 10B about an axisextending through the hinge pin and through the break in the cutter bar17 so that the wing section is supported at its inner end on the centersection but can pivot downwardly at its outer end so that the weight atthe outboard end is unsupported by the center section and causesdownward or counter clockwise pivotal movement of the wing section 10B.

The wing section 10C is mounted in an identical or symmetrical mannerfor pivotal movement about the other end of the center section 10A. Theamount of pivotal movement allowed of the wing section relative to thecenter section about the axis of the pivot pin is maintained at a smallangle generally less than 6° and preferably less than 4° as controlledby suitable mechanical stop members which are provided at a suitablelocation with the required mechanical strength to support the wing framesection against upward or downward movement beyond the stop members.Suitable stop members can be designed by a person skilled in the art andthe details of the stop members are not described herein.

The outboard weight of the wing section 10B is supported on aninterconnecting linkage 30 which communicates that weight from the innerend of the beam 14 of the section 10B through to the support for thecenter section 10A at the springs 24. The linkage is shown particularlyin FIGS. 4 and 5 as described in further detail below.

In general the linkage operates to transfer the outboard weight of thewing section inwardly to the center section and at the same time tobalance the lifting force provided by the springs 24 so that if isproportionally applied to the center section and to the wing section.

Thus in general the header is attached to the combine feeder house usingthe float system described previously that supports the header so thatit can be moved up when a vertical force about 1% to 15% of its weightis applied to the cutter bar from the ground. The reaction of the floatlinkage that typically supports 85% to 99% of the header weight on theheader is used to balance the weight of the wings.

The system is designed so that if the operator sets the float so thatthe float system supports 99% of the header weight then the remaining 1%will be evenly distributed across the cutter bar. If the operatorchanges the float so that 85% is supported by the combine harvester thenthe remaining 15% would also be evenly distributed across the cutter barwithout the operator making adjustments. Thus, not only is the totallifting force to each sections varied in proportion to the total liftingforce but also that lifting force on each section is balanced across thewidth of section. As the sections are rigid between the ends, thisrequires that the lifting forces be balance between the ends to ensurethe even distribution across the cutter bar of each section and thus ofall the sections. This provides an arrangement in which the forcerequired to lift the header is the same force at any location along thelength of the cutter bar, whether that location is at the centersection, at a junction between the center section and the wing sectionor at the wing section. This is achieved in this embodiment by thebalancing system which transfers lifting force between the sections withthe forces being balanced by a balance beam of the linkages 30.

The header frame sections and the reel sections are hinged and supportedso that the reel will stay in approximately the same position relativeto the cutter bar. Thus the balance beam as described in more detailhereinafter balances the lifting force applied to the ends of the centersection relative to the lifting force which is applied to the outboardweight of the wing section so that the lifting force is even across thewidth of the header. Thus if a lifting force is applied by the ground orany other lifting mechanism for example merely manually lifting theheader at a particular location across its width, that would cause theheader to rise at that point and to fall at other points. The amount offorce necessary to lift the header at that point will be the same as itis at other points and this lifting force can be varied for the totalheader and proportioned across the width of the header automatically bythe balance beams as described hereinafter.

It will be appreciated that the inboard weight of the wing section istransferred through the pivot 27 to the outboard end of the centersection and that weight is transferred directly to the balance beam.Also the outboard weight of the wing section is transferred through thelinkages 30. Yet further a lifting force from the arm 21 is applied tothe balance beam.

The whole support assembly including the linkages 30, the lift arm 21and the springs 24 are arranged to provide a floating movement for eachof the first and second frame portions that is the center and wing frameportions relative to each other and relative to the propulsion vehiclesuch that upward pressure from the ground on the skid element 16A whichis greater in a downward force for a part of the weight of the headerand supported by the lifting force tends to lift each of the center andwing frame portions relative to the propulsion vehicle.

The balance beam arrangement is arranged such that the first and secondlifting forces are varied proportionally as the total lifting forceF_(τ) is varied.

The height of the header is primarily controlled by controlling theheight of the feeder house 20 of the combine harvester relative to theground using a height control mechanism 100. Typically the feeder houseis pivotally supported on a main frame of the combine harvester and anactuator member is mounted between the feeder house and the main frameto raise and lower the feeder house.

The height of the main structure of the header is in turn supported forup and down movement relative to the adapter 11 by supporting the mainframe structure on the pivot arms 21 which are supported for floatingmovement by the springs 24 by providing a total spring lifting force tothe header. The linkages 30 in turn distribute this total spring forceinto a center lifting force F_(c) which provides lift to the centerframe section and the inboard ends of the wing frame sections pivotallycoupled thereto as well as a first lifting force and a second liftingforce acting upon the first and second wing frame sections respectivelyin a direction intending to cause the outboard ends of the wing framesto be raised upwardly.

The linkages 30 supporting the main frame structure on the pivot arms 21comprises two balance linkages associated with the two pivot armsrespectively. Each balance linkage includes a balance beam 102 pivotallysupported at an intermediate location between front and rear ends on theforward ends of the pivot arms 21. The forward ends of the two balancebeams 102 are pivotally connected to respective locations on the centersection of the main frame structure at transversely spaced apartlocations. The forward ends of the balance beams 102 serve to providethe center lifting force F_(c) to the main frame structure. The opposingrear ends of the two balance beams 102 provide the first and secondlifting forces to the first and second wing frame sections.

More particularly, the rear end of each balance beam 102 is pivotallyconnected to an upright compression link 104 which extends upwardly fromthe balance beam 102 below the main frame structure to a top end inproximity to a fop end of the main frame structure. Each balance linkagefurther includes a bell crank 106 pivotally supported on the main framestructure adjacent the top end in which the bell crank includes a firstlever 108 pivotally coupled to the top end of the respective compressionlink 104 and a second lever portion 110 extending upward to a pivotconnection with a respective tension link 112.

Pivotal connection of the second lever 110 with the respective tensionlink 112 is located substantially directly above the pivotal connectionof the bell crank to the main frame structure such that an upward forceacting on the compression link 104 tends to rotate the bell crank in adirection corresponding to a laterally inward tension on the tensionlink 112 which is pivotally coupled at its outer end to a respective oneof the wing frame sections which tends to pivot the wing frame sectionin a direction about its pivotal coupling to the center frame section ina direction corresponding to the outboard and of the wing frame sectionbeing raised upwardly.

The balance linkages 30 serve to balance the total lifting forceprovided by the combine harvester through the pivot arms 21 to thecenter lifting force at the forward ends of the balance beams 102 andthe first and second lifting forces at the rear ends of the balancebeams so as to vary the lifting forces as the total lifting force variesand so as to balance the lifting forces from the ground applied alongthe length of the skid element.

The header further includes a stop member 114 which is arranged to limitdownward movement of the main frame structure of the header relative tothe adapter. A distance sensor 116 is provided for sensing a distance ofa point on the header which moves with the header in suspension movementrelative to the bottom stop 114 which is stationary relative to thecombine harvester. The distance sensor therefore generates a signalindicative of the sensed changes in the measured distance. The heightcontrol mechanism 100 which is arranged to raise and lower the feederhouse of the combine harvester, receives the signal from the sensor 116as an input and is automatically operated so as to attempt to maintainthe sensed distance at a required set value. The set value is selectedso that the header is free to float between the bottom stop and theupper limited movement both upwardly and downwardly to accommodatechanges in ground height.

The gauge system 5 according to the present invention is particularlysuited for use with the above described header 10 to permit the headerto operate in a balanced manner with the wing sections floating relativeto the center section when operating at a raised cutting height with thecutter bar and skid member 16A supported well above the ground.

Thus as shown in FIGS. 1 to 5 there is provided a crop harvesting header10 with center and wing sections 10A, 10B and 10C. Each includes a mainframe structure so that together the combined frame structure extendsacross a width of the header. The main frame structure as best shown inFIGS. 7 and 8 includes a main frame beam 40 across the rear at the topof the header and a plurality of frame members 41 located at spacedpositions across the main frame structure. Each frame member 41 extendsfrom the frame beam 40 in a first portion 42 downwardly behind the table43 and in a second portion 44 forwardly under the table to support thecutter bar 45. The second portion 43 forms a channel member with adownwardly facing open face 46.

The frame structure is attached to a mounting assembly defined by theadapter 11 of FIG. 5 for carrying the main frame structure on the feederhouse 12 of a propulsion vehicle such as a combine harvester by whichthe header is transported in movement in a toward direction generally atright angles to the width across ground including a crop to beharvested.

The crop cut by the sickle knife 47 of the cutter 45 falls onto the cropreceiving table 44 carried on the main frame structure across the widthof the header.

A skid element 48 on the main frame structure is located just behind thesickle knife of the cutter bar for engaging the ground so as to receivelifting forces from the ground. The skid element 48 is located behindthe cutter bar and extends along the length of the cutter bar so thatthe cutter bar is supported adjacent the ground for cutting crop closeto the ground as the skid element 48 slides over the ground.

A crop transport system 49 such as a draper system or auger is providedon the table for moving the cut crop toward a discharge location of theheader. As described above, the harvesting header is operable in a firstmode of operation shown in FIG. 7 with the skid element 48 engaging theground and the cutter bar 45 adjacent the ground and in a second mode ofoperation shown in FIG. 8 with the skid element 48 and the cutter barraised away from the ground.

As explained previously and shown in FIG. 4, the first wing frameportion 10B is connected to the center frame portion 10A by a firstpivot coupling 102 which provides pivotal movement of the first wingframe portion 10B relative to the center frame portion 10A about a firstpivot axis extending in a plane parallel to the forward direction.Symmetrically the second wing frame portion 10C is mounted on the otherside if the center section.

The first pivot coupling 102 is provided to support weight from thefirst wing frame portion 10B while outboard weight from the first wingframe portion 10B outboard of the first pivot coupling rotates the firstwing frame portion 10B about the first pivot coupling in a downwarddirection. Symmetrically the second wing frame portion 10C is mounted onthe other side if the center section and supported by a symmetricalcoupling.

As explained previously, the mounting assembly including a floatsuspension system 24 connected to the center frame portion providing avariable lifting force from the propulsion vehicle acting to support themain frame structure for floating movement relative to the propulsionvehicle. A first interconnecting float linkage 108 is connected betweenthe center frame portion 10A and the first wing frame portion 10B whichcommunicates a first variable lifting force from the center frameportion to the first wing frame portion against the outboard weight ofthe first wing frame portion. A second symmetrical interconnectinglinkage communicates a second variable lifting force from the centerframe portion to the second wing frame portion against the outboardweight of the second wing frame portion.

In the first mode of operation with the skid element 48 engaging theground, the float suspension system 24 and first and secondinterconnecting linkages 108 provide a downforce from the skid element48 on the ground which is balanced between the center frame portion 10Aand the first and second wing frame portions 10B, 10C.

As set out hereinbefore, the above arrangements are conventional andfurther details can be obtained from the referenced patents or frommachines well known in the industry and manufactured by MacDon.

In accordance with the arrangement described herein, there is provided agauging system 50 used in the second mode of operation to hold thecutter bar in the raised position of FIG. 8.

This includes four separate ground engaging members 51 located in thepositions shown in FIG. 1. This includes a first ground engaging member51 supported on the first wing frame portion 10B at a location spacedoutwardly from the center frame portion and particularly at the outerend of the portion at the crop divider and end sheet of the header forengaging the ground so as to receive lifting forces from the ground, asecond ground engaging member 51 supported on the second wing frameportion 10C also at the outer end and two additional ground engagingmember 51 supported on the wing frame portions immediately proximate thecenter frame portion 10A for engaging the ground so as to receivelifting forces from the ground. The two additional members 51 can belocated on the center section. The outer members are preferably locatedat the ends but also can be moved inboard.

The location of the four ground engaging elements 51 at the locationsspecified provides a proper balance of the header relative to thenominal balance points P on the wing frame portions 10B and 10C. Thepoints P represent the locations where the three sections will bebalanced if supported by members at the points. It will be noted thatthe actual ground engaging members are located at spaced positions fromthese points. Thus the outermost member 51 is located at the outer endof the wing and the innermost member 51 is located closely adjacent thepivot coupling. These locations are spaced sufficiently from the pointsP so that ground forces transmitted to the frame through the members 51will allow the wings to flex around the pivot points and keep all threesections at a common spacing from the ground.

In the embodiment of FIGS. 6 to 9, each of the ground engaging members51 has a surface arrangement defined by the periphery 53 of a pair ofwheels 54 carried on an axle 55. The surface 53 engages the ground at aposition rearwardly of the cutter bar and underneath the table suchthat, in the second mode of operation, the ground engaging memberscollectively support the skid element 48 spaced above the ground whilethe first and second wing frame portions are allowed to pivot relativeto the center frame portion in response to changes in ground height.

The wheels 54 defining each of the surface arrangements are mounted bythe axle 55 on an elongate support member 56 connected at a forward end57 adjacent to and rearwardly of the cutter bar 47 for pivotal movementabout an axis 58 parallel to the cutter bar 47. The elongate supportmember 56 forms a rigid beam arranged to be raised and lowered to raiseand lower the wheels 54 and the surface arrangement 53 defined thereby;

As shown in FIG. 8, each of the wheels is fully retractable, by raisingof the elongate support member or beam 56 to an uppermost raisedposition within the channel 43, to a height of the wheel underneath thetable to cause the skid element 48 or cutter bar polymer shield toengage and run across the ground in the first mode of operation cuttingat ground level. In this mode the header will ride either on the cutterbar shield or on the skid shoe depending on the header angle.

Thus the first and second ground engaging members are mounted atrespective outer ends of the first and second wing frame portions andthe two inner additional ground engaging members 51 are mounted on thefirst wing frame portion closely adjacent to the pivot axis and on thesecond wing frame portion closely adjacent the pivot axis. In the secondmode of operation and in this arrangement where the ground engagingmembers are mounted only on the wing sections, the center frame portionis supported only by said float suspension system and not by anyadditional ground engaging members 51.

Each of the elongate support beams 56 extends rearwardly under the tableto a rear end 59 rearward of the table. At the rear end there isprovided an upstanding telescopically extendible member 60 connected ata lower end 61 to the elongate support beam 56 and to a lug 63 of theframe structure at the upper end 62 rearward of the table to raise andlower the beam relative to the frame and thus the cutter bar relative tothe ground.

As best shown in FIGS. 10 and 11 the extendible member comprises a pairof telescopic members 65 and 66 including an outer member 65 with aninner member 66 slidable within the outer member. The inner member 66has a plurality of longitudinally spaced holes 67 for receiving a pin 68of the outer member to locate the inner and outer members at anextension position defined by the selected hole. The holes 67 are spacedalso transversely across the inner member and the pin is carried on arotatable member 69 which acts when rotated to move the pin 68transversely across the outer member into a selected one of a pluralityof holes 70 so that the transverse position of the pin is adjusted asthe member 69 is rotated and when rotated acts automatically to selectone of the holes of the inner member, thus determining the telescopiclength of the member 60. The elongate support members are each locatedin a second channel portion 46 of a respective one of said frame members41 and extends rearwardly under the table to the rear member 60 foradjustment.

Each of the ground engaging surfaces 53 is located under the table sothat it is forward of the rear of the table. Thus when raised, theamount of movement allowed is relatively small. In order to achieve therequired height of the cutter bar of at least 12 inches and preferablygreater than 14 inches, the mounting assembly includes the tilt cylinder26 connected to the frame structure of the header for tiling the framestructure and the cutter bar carried thereby forwardly and rearwardly.Thus when actuated by a switch 72 the tilt cylinder can be retracted topull the front of the header upwardly to further increase the height ofthe cutter bar, although the arrangement described herein provides arequired height of the cutter bar even without the tiling action of thecylinder 26.

In a case where the manual adjustment of the member 60 is replaced by ahydraulic cylinder, common operation of the lowering of the elongatesupport members 60 and the tilt cylinder causes the cutter bar to beraised such that the cutter bar is located at a cutting height from theground of greater than 12 inches.

As shown in FIGS. 6, 7 and 8, the forward end 57 of the member 56 caninclude a skid plate 73. The forward end is pivotally connected to atransverse mounting pin attached to the frame behind the skid element48. Suitable lugs are attached to the frame member 41 at the forward endto receive the pin. As an alternative, the skid plate 73 can form a partof the header and is mounted to the frame permanently by a pin forpivotal movement about the pin. In this arrangement the toward end ofthe member 56 is attached by a coupling to the skid plate.

As shown in FIGS. 6 and 9, the axle 55 of the wheels 54 is mounted on asuspension linkage 74 which allows the axle to move up and down on thelinkage about a pivot pin 75 at the forward end with a resilient blockor spring 76 resisting the upward movement of the wheels toward themember 56. This provides a resilient suspension arrangement between theelongate support member and the wheels allowing up and down floatingmovement of the wheels.

In FIGS. 12, 13 and 14 is shown an alternative arrangement where thesurface arrangement for engaging the ground comprises a skid surface 77which extends from a forward edge 78 effectively as a continuous slidesurface rearwardly to a rear end 79 at the extendible member 60 justbehind the rear edge of the table. The surface 77 thus forms acontinuous surface which slides over the ground from a front edge at aposition adjacent the cutter bar to a position at least adjacent to therear edge of the table. As shown in the cross-sections of FIGS. 13 and14, the skid surface 77 is arched both longitudinally and transversely.

The skid surface is carried on the member 56 as a permanent attachmentthereto and can be used alone to run over the ground. Alternatively theskid member can be used in conjunction with a pair of ground wheels 54Amounted on the member 56 by a suspension arrangement similar to thatpreviously described. Thus when the wheels are used they can floatupwardly relative to the skid surface so that primarily the wheels runon the ground and provide the support. The wheels can be removed in someconditions such as heavy mud where they may be ineffective or maycollect mud. That is the wheel arrangement is removable to allow theskid surface to slide on the ground.

As can be seen in FIGS. 6 and 12, the wheel assemblies pivot near thecutter bar and have a short skid 57 that is pail of the structure thatthe header would only ride on when cutting directly on the ground. Thedevice of FIG. 6 comprises a short skid shoe 57 on the leading edge nearthe cutting edge of the header with a member 56 extending rearwardallowing the attachment of ground following wheels 54 and an adjustmentdevice 60 at the rear of the header.

The location of the four wheel assemblies where are at each end of theheader, and two are near the hinge points as displayed in FIG. 1 ensuresenough moment about the virtual balance point of the header to overcomefriction and cause the header to flex. This allows the operator to usethe header while in flex mode in order to achieve better groundfollowing while cutting as high as 18″ off the ground.

The wheel assembly contains an isolator 74 to aid in eliminating headerbounce and stress on components as the wheels travel over bumps andother incompressible objects. One embodiment of the isolator consists ofa torsional rubber isolator which is mounted to the member 76 that spansfrom the cutter bar to the rear adjuster. In this case, the wheelassembly 54 and axle 55 which contains two links is bolted to thetorsional isolator 76. As the wheel 54 strikes an object, the linksconvert the force into a moment which causes the isolator 74 to rotateand absorb the load.

The means of adjusting the height of the wheel assembly can be a manualadjuster such as is explained later or a hydraulic wheel heightadjustment system. With the manual adjuster, the operator would set allfour adjusters to a height which is close to the desired cut height andfine adjustments can then be made to the cut height by changing the tiltof the header using the cylinder 26. With the hydraulic adjustment whichcontains four hydraulic cylinders in a series circuit in a master slavearrangement, and a switch 72 in the combine cab, the operator can adjustthe height of the wheels by actuating the cylinders using the in cabswitch while harvesting.

The long skid shoe embodiment of FIGS. 12, 13 and 14 consists of amember positioned such that the header rides on the shoes when incutting position. The operator may choose to retract the shoes such thatthe header can cut on the ground, effectively removing the long skidshoes from operation. This enables the operator to adjust cut heightsuch that a desired stubble length can be achieved. The embodiment shownallows for a stubble height ranging from 1.25″ up to 14″.

The long shoe 77 may either be integrated into standard short skid shoes57 near the front of the header, or exist in addition to short standardskid shoes 57.

The wheels 54A can be permanently attached to the skid shoe or removableas desired.

The wheels 54, 54A may consist of a variety of materials, including asolid material as shown in this embodiment, or a pneumatic wheel.

The wheels 54 may be fixed position along the member 56 or include anadjustable member (not shown) such that the distance of the wheel fromthe cutter bar may be altered.

The wheels 54A may be used to increase the stubble height beyond therange of the shoe. In this embodiment, 18 inches may be achieved usingthe wheels. The wheels 54A offer ail of the benefits of the skid shoe,while increasing the life of the device in abrasive conditions, as wellas reducing friction.

The preferred method of providing shock absorption is to install aresilient isolator 80 at the connection of the vertical post 60 and rearof the beam 56 carrying the skid shoe member 77. The isolator provides ahinge with a resilient rubber restrictor at the hinge which providesflexibility between the rear of the skid and the post 60 so that theskid can ride up and down to accommodate changes in terrain. Variousarrangements for providing flexibility at this location are possible.

The invention claimed is:
 1. A crop harvesting header comprising: a mainframe structure extending across a width of the header; a connectionassembly carrying the main frame structure on a propulsion vehicle inmovement in a forward direction at right angles to the width acrossground including a crop to be harvested; a crop receiving table carriedon the main frame structure across the width of the header; a cutter baracross a front of the table which moves through the crop in a cuttingaction and carrying a sickle knife which cuts the crop as the header ismoved forwardly; a crop transport system on the table; a skid elementengaging the ground adjacent the cutter bar; the skid element extendingalong the length of the cutter bar so that the cutter bar is supportedadjacent the ground as the skid element slides over the ground; theharvesting header having a first position of the header in which theskid element engages the ground and a second position of the header inwhich the skid element is raised away from the ground; and at least oneground engaging gauge member having a surface arrangement mountedthereon rearward of the cutter bar with the surface arrangement in thesecond position supporting the skid element away from the ground; amounting assembly of the ground engaging gauge member comprising anelongate support member connected at a forward end to the main framestructure at a position rearward of the cutter bar and forward of therear of the table by a pivot coupling providing pivotal movement of theelongate support member about an axis parallel to the cutter bar, theelongate support member extending rearwardly from the pivot coupling atthe forward end; an adjustment device which raises and lowers theelongate support member to raise and lower the surface arrangementbetween said first and second positions of the header; wherein thesurface arrangement comprises a skid member with a bottom skid surfacewhich slides over the ground, the skid member having a front edge of thebottom skid surface at the pivot coupling and a rear edge of the bottomskid surface at least adjacent to the rear edge of the table.
 2. Thecrop harvesting header according to claim 1 wherein the skid surface isarched both longitudinally and transversely.
 3. The crop harvestingheader according to claim 1 wherein: the main frame structure includes acenter frame portion, a first wing frame portion and a second wing frameportion; the first wing frame portion is connected to the center frameportion by a first pivot coupling which provides pivotal movement of thefirst wing frame portion relative to the center frame portion about afirst pivot axis extending in a plane parallel to the forward direction;the first pivot coupling acts to support weight from the first wingframe portion while outboard weight from the first wing frame portionoutboard of the first pivot coupling rotates the first wing frameportion about the first pivot coupling in a downward direction; thesecond wing frame portion is connected to the center frame portion by asecond pivot coupling which provides pivotal movement of the second wingframe portion relative to the center frame portion about a second pivotaxis extending in a plane parallel to the forward direction; the secondpivot coupling acts to support weight from the second wing frame portionwhile outboard weight from the second wing frame portion outboard of thesecond pivot coupling rotates the second wing frame portion about thesecond pivot coupling in a downward direction; the connection assemblyincludes a float suspension system connected to the center frame portionproviding a variable lifting force from the propulsion vehicle acting tosupport the main frame structure for floating movement relative to thepropulsion vehicle; a first interconnecting float linkage is connectedbetween the center frame portion and the first wing frame portion whichcommunicates a first variable lifting force from the center frameportion to the first wing frame portion against the outboard weight ofthe first wing frame portion; a second interconnecting linkage isconnected between the center frame portion and the second wing frameportion which communicates a second variable lifting force from thecenter frame portion to the second wing frame portion against theoutboard weight of the second wing frame portion; in the first positionwith the skid element engaging the ground, the float suspension systemand first and second interconnecting linkages provide a downforce fromthe skid element on the ground which is balanced between the centerframe portion and the first and second wing frame portions.
 4. The cropharvesting header according to claim 3 wherein said first and secondground engaging gauge members are mounted at respective outer ends ofthe first and second wing frame portions said additional ground engaginggauge member comprises a first additional ground engaging gauge membermounted on the first wing frame portion closely adjacent to the pivotaxis and a second additional ground engaging gauge member is mounted onthe second wing frame portion closely adjacent the pivot axis, andwherein the center frame portion is supported only by said floatsuspension system and not by any one of said additional ground engaginggauge members.
 5. The crop harvesting header according to claim 1wherein said at least one ground engaging gauge member is fullyretractable by raising of the elongate support member to a heightunderneath the table to cause the skid element to engage the ground. 6.The crop harvesting header according to claim 1 wherein said elongatesupport member extends rearwardly under the table to a rear end rearwardof the table and there is provided an upstanding extendible memberconnected at a lower end to the elongate support member and to the framestructure above the lower end and rearward of the table to raise andlower the cutter bar relative to the ground.
 7. The crop harvestingheader according to claim 6 wherein the extendible member comprises apair of telescopic members with an outer with an inner member slidablewithin an outer member, wherein the inner member has a plurality oflongitudinally spaced holes for receiving a pin of the outer member tolocate the inner and outer members at an extension position defined bythe selected hole, wherein the holes are spaced transversely of theinner member and the pin is carried on a rotatable member which actswhen rotated to move the pin transversely across the outer member sothat the transverse position of the pin when rotated acts automaticallyto select one of the holes of the inner member.
 8. The crop harvestingheader according to claim 1 wherein the main frame structure includes aframe beam and a plurality of frame members located at spaced positionsacross the main frame structure; each frame member extending from theframe beam in a first portion downwardly behind the table and in asecond portion forwardly under the table to support the cutter bar; thesecond portion forming a channel member with a downwardly facing openface; the elongate support members each being located in a secondportion of a respective one of said frame members and extendingrearwardly under the table.
 9. The crop harvesting header according toclaim 1 wherein said arrangement is located under the table.
 10. A cropharvesting header comprising: a main frame structure extending across awidth of the header; a connection assembly for carrying the main framestructure on a propulsion vehicle in movement in a forward direction atright angles to the width across ground including a crop to beharvested; a crop receiving table carried on the main frame structureacross the width of the header; a cutter bar across a front of the tablewhich moves through the crop in a cutting action and carrying a sickleknife which cuts the crop as the header is moved forwardly fordepositing the crop onto the table; a crop transport system on the tablewhich carries the cut crop toward a discharge location of the header; askid element engaging the ground behind the cutter bar; the skid elementextending along the length of the cutter bar so that the cutter bar issupported adjacent the ground as the skid element slides over theground; the harvesting header having a first position of the header inwhich the skid element engages the ground and a second position of theheader in which the skid element is raised away from the ground; and atleast one ground engaging gauge member having a surface arrangementmounted thereon rearward of the cutter bar with the surface arrangementand in the second position supporting the skid element away from theground; a mounting assembly of the ground engaging gauge membercomprising an elongate support member connected at a forward end to themain frame structure at a position rearward of the cutter bar andforward of a rear edge of the table by a pivot coupling providingpivotal movement of the elongate support member about an axis parallelto the cutter bar, the elongate support member extending rearwardly fromthe pivot coupling at the forward end; an adjustment device which raisesand lowers the elongate support member to raise and lower the surfacearrangement between said first and second positions of the header;wherein the surface arrangement comprises: a skid member with a bottomskid surface which slides over the ground, the skid member having afront edge of the bottom skid surface at the pivot coupling and extendsrearwardly therefrom; and at least one wheel arrangement rotatable abouta wheel axle carried on the elongate support member at a positionrearward of the pivot coupling and forward of the rear edge of thetable.
 11. The crop harvesting header according to claim 10 wherein thewheel arrangement is removable to allow the skid surface to slide on theground.
 12. The crop harvesting header according to claim 10 whereinthere is provided a resilient suspension arrangement which providesmovement between the surface arrangement and the mounting to the frameof the header.
 13. The crop harvesting header according to claim 10wherein the wheel arrangement comprises a pair of wheels each on arespective side of the skid with transverse axis of rotation across thetop of the skid allowing the wheels to rise relative to the skid. 14.The crop harvesting header according to claim 10 wherein the skidsurface is arched both longitudinally and transversely.
 15. The cropharvesting header according to claim 10 wherein: the main framestructure includes a center frame portion, a first wing frame portionand a second wing frame portion; the first wing frame portion isconnected to the center frame portion by a first pivot coupling whichprovides pivotal movement of the first wing frame portion relative tothe center frame portion about a first pivot axis extending in a planeparallel to the forward direction; the first pivot coupling acts tosupport weight from the first wing frame portion while outboard weightfrom the first wing frame portion outboard of the first pivot couplingrotates the first wing frame portion about the first pivot coupling in adownward direction; the second wing frame portion is connected to thecenter frame portion by a second pivot coupling which provides pivotalmovement of the second wing frame portion relative to the center frameportion about a second pivot axis extending in a plane parallel to theforward direction; the second pivot coupling acts to support weight fromthe second wing frame portion while outboard weight from the second wingframe portion outboard of the second pivot coupling rotates the secondwing frame portion about the second pivot coupling in a downwarddirection; the connection assembly includes a float suspension systemconnected to the center frame portion providing a variable lifting forcefrom the propulsion vehicle acting to support the main frame structurefor floating movement relative to the propulsion vehicle; a firstinterconnecting float linkage is connected between the center frameportion and the first wing frame portion which communicates a firstvariable lifting force from the center frame portion to the first wingframe portion against the outboard weight of the first wing frameportion; a second interconnecting linkage is connected between thecenter frame portion and the second wing frame portion whichcommunicates a second variable lifting force from the center frameportion to the second wing frame portion against the outboard weight ofthe second wing frame portion; in the first position with the skidelement engaging the ground, the float suspension system and first andsecond interconnecting linkages provide a downforce from the skidelement on the ground which is balanced between the center frame portionand the first and second wing frame portions.
 16. The crop harvestingheader according to claim 10 wherein said at least one ground engaginggauge member is fully retractable by raising of the elongate supportmember to a height underneath the table to cause the skid element toengage the ground.
 17. The crop harvesting header according to claim 10wherein said elongate support member extends rearwardly under the tableto a rear end rearward of the table and there is provided an upstandingextendible member connected at a lower end to the elongate supportmember and to the main frame structure above the lower end and rearwardof the table to raise and lower the cutter bar relative to the ground.18. The crop harvesting header according to claim 17 wherein theextendible member comprises a pair of telescopic members with an outerwith an inner member slidable within an outer member, wherein the innermember has a plurality of longitudinally spaced holes for receiving apin of the outer member to locate the inner and outer members at anextension position defined by the selected hole, wherein the holes arespaced transversely of the inner member and the pin is carried on arotatable member which acts when rotated to move the pin transverselyacross the outer member so that the transverse position of the pin whenrotated acts automatically to select one of the holes of the innermember.
 19. The crop harvesting header according to claim 10 wherein themain frame structure includes a frame beam and a plurality of framemembers located at spaced positions across the main frame structure;each frame member extending from the frame beam in a first portiondownwardly behind the table and in a second portion forwardly under thetable to support the cutter bar; the second portion forming a channelmember with a downwardly facing open face; the elongate support memberseach being located in a second portion of a respective one of said framemembers and extending rearwardly under the table.
 20. A crop harvestingheader comprising: a main frame structure extending across a width ofthe header; a connection assembly carrying the main frame structure on apropulsion vehicle in movement in a forward direction at right angles tothe width across ground including a crop to be harvested; a cropreceiving table carried on the main frame structure across the width ofthe header; a cutter bar across a front of the table which moves throughthe crop in a cutting action and carrying a sickle knife which cuts thecrop as the header is moved forwardly for depositing the crop onto thetable; a crop transport system on the table which carries the cut croptoward a discharge location of the header; a skid element for engagingthe ground behind the cutter bar; the skid element extending along thelength of the cutter bar so that the cutter bar is supported adjacentthe ground as the skid element slides over the ground; the harvestingheader having a first position of the header in which the skid elementengages the ground and a second position of the header in which the skidelement is raised away from the ground; and at least one ground engaginggauge member having a surface arrangement mounted thereon rearward ofthe cutter bar with the surface arrangement and in the second positionsupporting the skid element away from the ground; a mounting assembly ofthe ground engaging gauge member comprising an elongate support memberconnected at a forward end to the main frame structure at a positionrearward of the cutter bar and forward of the rear of the table by apivot coupling providing pivotal movement of the elongate support memberabout an axis parallel to the cutter bar, the elongate support memberextending rearwardly from the pivot coupling at the forward end; anadjustment device which raises and lowers the elongate support member toraise and lower the surface arrangement between said first and secondpositions of the header; wherein the surface arrangement comprises atleast one ground wheel rotatable about a wheel axle mounted on theelongate support member for rotation about an axis parallel to thecutter bar at a position rearward of the pivot coupling and forward ofthe rear edge of the table; and wherein there is provided a resilientsuspension arrangement which provides suspension movement between theground wheel and the mounting to the main frame structure.
 21. The cropharvesting header according to claim 20 wherein said at least one groundengaging gauge member is fully retractable by raising of the elongatesupport member to a height underneath the table to cause the skidelement to engage the ground.
 22. The crop harvesting header accordingto claim 20 wherein said at least one ground engaging gauge memberextends rearwardly under the table to a rear end rearward of the tableand there is provided an upstanding extendible member connected at alower end to the elongate support member and to the frame structureabove the lower end and rearward of the table to raise and lower thecutter bar relative to the ground and wherein the resilient suspensionarrangement is located at the rear of the elongate support member at theconnection to the extendible member.